Frontotemporal dementia often misdiagnosed due to misinterpretations of imaging
Incorrect interpretations of medical images could play a significant role in the misdiagnosis of frontotemporal dementia, new data suggest.
Diagnosing frontotemporal dementia is notoriously difficult. It includes behavioral and neurological assessments, a thorough medical examination, interviews with family members and imaging of the brain. Due to the subjectivity of some of these assessments, the condition often is diagnosed incorrectly.
According to new research out of the University of Queensland, misdiagnosis could occur in as many as 70% of cases. The reasons for misdiagnoses are wide-ranging, but interpretations of patients’ brain imaging may play a prominent role, authors involved in the analysis suggest.
“The behavioral variant of frontotemporal dementia (bvFTD) is a challenging diagnosis due to overlapping symptoms with psychiatric and other neurological conditions,” Joshua Flavell, with The Queensland Brain Institute in Australia, and colleagues note. “Accordingly, misdiagnosis is common. The present study aimed to identify clinical factors contributing to misdiagnoses of bvFTD by specialist physicians.”
For their work, researchers retrospectively analyzed 100 consecutive referrals from specialists to a cognitive disorder clinic specializing in frontotemporal lobar degenerative disorders. The team compared patients’ medical histories, imaging and other diagnostic exams alongside their final diagnoses to determine which referrals resulted in true identification of the condition.
Of the 100 cases included, just 34 were considered true positives. One-third of the false positives were owed to misinterpretations of imaging, particularly nuclear imaging (FDG-PET and HMPAO-SPECT).
“An erroneous bvFTD diagnosis frequently related to subjective interpretation of frontotemporal hypoperfusion or hypometabolism, often without quantitative confirmation,” the authors explain. “This finding is consistent with previous research, which emphasized that while imaging can be a valuable tool for diagnosing bvFTD, it requires careful and accurate interpretation—qualitative visual assessments by radiologists have shown low specificity in diagnosing bvFTD and have been outperformed by quantitative assessment methods.”
Subjective analyses of neurocognitive exams were the second most impactful factor, leading to misdiagnosis in 20 of the cases studied. The team also found that patients with a history of psychiatric disorders were more likely to be incorrectly labeled as having frontotemporal dementia.
Though the team described the observed misdiagnoses as “exceedingly prevalent,” they expressed optimism for addressing the problem.
“On an optimistic note, the results suggested that the number of misdiagnoses could be considerably reduced by improving awareness of the dangers of over-interpretation of neuroimaging and neuropsychological assessments,” they suggest. “Physicians must remain especially vigilant to the presence of past psychiatric illness and place particular weight on objective behavioral observations and neurological examination during assessments.”
Learn more about the findings here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.